Method of manufacturing semiconductor device

Abstract

The present invention relates to a method of manufacturing a semiconductor device by which the length of nanowires perpendicularly formed can be fabricated with high reproducibility. The method of manufacturing a semiconductor device includes the steps of forming a first layer; forming a stop layer on the first layer, the stop layer having a higher Young's modulus than the first layer; forming a recess by partially removing the first layer and the stop layer; growing nanowires in the recess; forming a planarizing layer; removing the planarizing layer to the level of the stop layer to expose the nanowires from the surface of the planarizing layer; and forming an electrode so as to be in contact with the upper ends of the nanowires.

The invention claimed is: 
     
       1. A method of manufacturing a semiconductor device comprising the steps of:
 forming a first layer on a substrate; 
 forming a stop layer on the first layer, the stop layer having a higher Young's modulus than the first layer; 
 forming a recess by partially removing the first layer and the stop layer such that a portion of the substrate is exposed; 
 growing nanowires extending in a direction perpendicular to a surface of the substrate in the recess such that the length of the nanowires is larger than the sum of the thickness of the first layer and the thickness of the stop layer; 
 forming a planarizing layer in the recess in which the nanowires have been grown, the planarizing layer having a thickness larger than the sum of the thickness of the first layer and the thickness of the stop layer and having a lower Young's modulus than the stop layer; 
 removing the planarizing layer to the level of the stop layer to expose the nanowires from the surface of the planarizing layer; and 
 forming an electrode so as to be in contact with the upper ends of the nanowires. 
 
     
     
       2. The method of manufacturing a semiconductor device according to  claim 1 , further comprising the steps of:
 forming an insulating layer so as to cover the nanowires, the substrate, and the electrode which have been exposed at the recess; and 
 disposing a conductive substance in the recess provided with the insulating layer. 
 
     
     
       3. The method of manufacturing a semiconductor device according to  claim 1 , wherein, in the step of growing nanowires, a catalyst is deposited on the exposed portion of the substrate, and by supplying a gas containing atoms of a semiconductor that can form a eutectic with the catalyst, the nanowires composed of the semiconductor are grown. 
     
     
       4. The method of manufacturing a semiconductor device according to  claim 1 , wherein the stop layer has a Young's modulus of 200 GPa or more. 
     
     
       5. The method of manufacturing a semiconductor device according to  claim 1 , wherein the first layer is an insulating layer having a thickness larger than that of the stop layer and a Young's modulus of less than 100 GPa. 
     
     
       6. The method of manufacturing a semiconductor device according to  claim 1 , wherein the step of removing the planarizing layer is carried out by chemical mechanical polishing. 
     
     
       7. The method of manufacturing a semiconductor device according to  claim 1 , further comprising the steps of:
 forming an insulating layer so as to cover the nanowires, the substrate, and the electrode which have been exposed at the recess; and 
 disposing a material that specifically reacts with a target molecule on the insulating layer.